Mechanical pencil



' 2, 1941- TOMATSU MECHANICAL PENCIL Filed April 12, 1940 ATTORNEY tubes.2 connected ring It is fitted to its outside.

Patented Dec. 2, 1%1

MEG i CAL QENCIL Japan Application April 12, 1940, Serial No. 329.37%lin Japan December 23, 1939 3 Claims. (01. 120-14) The present inventionrelates to a mechanical pencil, which may conveniently be made byproviding an inclined projection on each of two depressible push tubesconnected with a slitted lead tube; inserting said lead tube into a leaddelivery tube -fitted with a lead holder, and said lead delivery tribeinto a sliding tube which has a window to allow the lead holder to go inand out; securing by a pin a spring tube which has a head, to the top ofa push rod provided with intersecting helical grooves; putting a springinto said spring tube and fitting a. rotatable ring to its outside;suspending a cap rotatably at the lower end of said ring; connecting thetwo push tubes to the sides of the push rod in sucha manner that one-issituated above the other; inserting the inclined projections into thehelical grooves, putting them all into an outer cylinder and thenfitting the cap to its top fixedly. The object thereof is to obtain amechanical pencil capable of containing leads of several colours andpushing them out successively by a comparatively simple mechanism.

Referring to the appended drawing,

Figure 1 is an elevation partly in section of the mechanical pencilaccording to the present in-.

vention;

Figure 2, a sectional view of the same;

Figure 3, a perspective view of the push tube;

Figure 4, a sectionalview oi the end of the pencil and I Figure 5, aplan of the head of the pencil.

In this invention, an inclined projection 3 is provided on each of thetwo depressible push with a lead tube I having a slit 6, which tube isinserted into a lead delivery tube 6 fitted with a lead holder 5. Thelead delivery tube is inserted into a sliding tube 1 which has a window8 to allow the lead holder to go in and out. A spring tube l2 having ahead it is fixed by apin lit to the top of apush rod Ill provided withintersecting helical grooves 9. A spring i5 is placed in tube i2 and arotatable At the lower end of said ring there depends a rotatable capIt. The push tubes 2, 2 are connected. to the sides of said push rod illin such a manner that one is situated above the other. The inclinedprojections 3 are adapted to engage in the helical grooves 9 and slidein that condition. .Next, they are'put ,into' an. outer cylinder ii andthenthe can It is fitted fixedly to its upper end. The push tubes .2, .2are hollow to receive leads and communicate with the lead tube throughholes at is pierced by an inlet. it for leads. I9 is a clip;-

20, a seat for the clip and 2|, 9. spring.

With the above construction, if the rotatable ring It is rotated toeither the right or left as desired, the inclined projections of thepush tubes engaged in the push rod l0 formed integrally with that ringit are moved up and down to move the push tubes and consequently advanceone of the push tubes (while the other recedes) until the .end of thelead tube is projected from the end of the outer tube l'l. Next, pressthe head it repeatedly several times, and then the push rod I0, pushtube 2 and lead tube lwill move up and down in one body to push out theleads in succession.

The present invention thus has a great practical advantage of ,beingable to contain leads of substantially axially of said casing andextendseveral colours and push them out in succession by a comparativelysimple mechanism.

I claim:

l. A mechanical pencil comprising a casing; a rotatable and depressiblepush rod mounted ing along substantially the upper half thereof, saidpush rod being provided with a plurality of oppositely arranged,intersecting-helical grooves extending along the length thereof; aplurality v of push tubes mounted for advancing and receding movement,one on each side of said push rod, each said push tube being providedwith an inclined lug extending into operative engagement with one ofsaid helical groove's, lead-holding means depending from said severalpush tubes; said parts being so constructed and arranged that rotationof said push rod advances one of said push tubes toward writing positionand simultaneously withdraws the other from such position, saidlead-holding means comprising a slitted lead tube, and means actuableupon depression of said depressible. push rod to advance lead from saidlead-holding means. a

2. A mechanical. pencil comprising a casing; a rotatable and depressiblepush rod mounted substantially axially of said casing and extendingalong substantially the upper half thereof,

' said push rod being provided with a plurality of their lower ends. Theupper surface of the cap oppositely arranged, intersecting helicalgrooves extending along the length thereof; a plurality of push tubesmounted for-advancing and receding movement, one on'each side of saidpush rod, each said push tube being provided with an inclined lugextending into operative engagement with one of said helical grooves,lead-holding means depending .from said. several push tubes;

said parts being so constructed and arranged that i rotation of saidpush rod advances one of said push tubes toward writing positon andsimultaneously withdraws the other from such position, said push tubesconstituting lead-containing reservoirs, and means on said casing havingopenings alignable with the respective push tubes whereby leads may besupplied to said tubes.

3. A mechanical pencil comprising a casing; a rotatable and depressiblepush rod mounted substantially axially of said casing and extendingalong substantially the upper half thereof, said push rod being providedwith a plurality of oppositely arranged, intersecting helical groovesextending along the length thereof, a plurality of push tubes mountedfor advancing and receding movement, one on each side of said push rod,each said push tube being provided with an inclined lug extending intooperative engagement with one of said helical grooves, lead-holdingmeans depending from said several push tubes; said parts being soconstructed and arranged that rotation of said push rod advances one ofsaid push tubes toward writing position, said push tubes constitutinglead-containing reservoirs,

and means on said casing having openings align-

